Shen Nuo looked flustered, she was holding a mobile phone in her hand, and as soon as the door opened, she crashed directly into my arms. After seeing that it was me, Shen Nuo was slightly stunned, and then asked me where I had gone at night. Shen Nuo is indeed very worried about me, she must have known about my investigation at the police station.

But only Shen Cheng and I know about going to the construction site.

"Investigate the case." I replied.

Shen Nuo glanced at me and prepared to leave. It was already early in the morning, and I stopped her: "I have something to ask you." ”

Shen Nuo stopped, waiting for me to speak.

"Where are you going so late?" I asked.

Shen Nuo: "There is an emergency. That's what you're asking? ”

Me: "Your brother told me something, and I want to confirm it from you." ”

Soon, Shen Nuo became nervous: "What did he tell you, don't believe him!" ”

Shen Nuo's strange behavior made me think about it carefully, and Shen Nuo didn't seem to want me to know something, but there was no way for me to guess. Shen Nuo's face was a little haggard, and she hadn't slept well in the days she had taken care of me.

"What does your brother mean when he says he's a dead man?" I asked tentatively.

Shen Nuo was not as surprised as I imagined, on the contrary, she breathed a long sigh of relief, it seems that Shen Nuo has something that she doesn't want me to know more than that fire. After Shen Nuo breathed a sigh of relief, she immediately shook her head, saying that she didn't understand what I was saying.

"What the hell is going on with that fire?" I didn't give up and continued to ask.

Shen Nuo bypassed me and avoided the topic directly, she said that she had something urgent, and after speaking, she disappeared into the corridor, I thought about it and followed. When I walked out of the hotel, Shen Nuo got into a car, and before I could see the license plate number, the car disappeared into the vast night.

Answering the hotel again, I recalled the things that started with Shen Nuo, and I tried to deduce from the memories that the two siblings deliberately concealed something about me. But I didn't come up with anything until I thought about it.

When I left the hotel the next day, I knocked on Shen Nuo's door, but Shen Nuo had not returned. In order to confirm her safety, I called her, and Shen Nuo answered the phone quickly, and her answer was weak, as if she was very depressed. After she told me she was fine, she hung up the phone.

When he arrived at the police station, Shen Cheng was sitting in the office. There were several documents on the desk, and Shen Cheng pointed to them: "I haven't read the trace report on the scene yet." ”

Me: "Vice Captain Shen, you don't have to start everything with me at the same time for the sake of fairness, so you may miss the best opportunity to solve the case." ”

Shen Cheng didn't care: "It's not bad at this time, the case always has to be solved, isn't it?" ”

So far, the police don't have many clues, but Shen Cheng looks like he's swearing. I didn't answer him, picked up the appraisal report on the table, and at the same time, Shen Cheng also got up from his chair and opened the same other report.

The final autopsy report was not different from the preliminary autopsy report, and I focused on the many reports that were extracted from the corpse scene.

In the vicinity where the body was found, only the footprints of one person were found, which were the deceased's own. The construction site has been suspended for more than ten days, and due to the heavy rain, the footprints left by the workers in the construction site have been completely destroyed. The police conducted a carpet search of the construction site, but in the end they were unable to extract suspicious footprints.

Thinking back to what those workers said and what Shen Cheng and I saw with our own eyes last night, the position where the figure stood was very remote, and the corners were overgrown with weeds, so he stepped on the weeds. Due to the high humidity in Chongqing, the weeds are full of water traces at night, and if it is a relatively clean sole, stepping on the weeds, it is difficult for the police to extract potential footprints.

Shen Cheng and I have carefully observed the scene of the corpse, and the place where the corpse is lying has not been deliberately cleaned up, that is to say, on the day of the crime, the murderer did not even stand near the position where the corpse was lying, but went directly to the building and pushed the boulder.

It's a bit strange that the killer can kill the victim in such a situation.

Continuing to scroll through the appraisal report, there are many footprints left in the building, which are easy to destroy due to the sand and dust. Through comparison, the police found the owner of each pair of footprints, which belonged to the worker and the person in charge of the construction party, and other than that, the police were unable to find any other traces.

The murderer must have been to that building, leaving no footprints for the police to investigate, and must have used some kind of cover-up. Sure enough, the appraisal report listed a square trace, and through technical restoration, I could see the scene in the photograph clearly: the steps from the first floor to the thirteenth floor and the dusty floor left one square mark after another.

If the speculation is correct, the murderer tied something similar to a square wooden board to his cry to prevent footprints.

The mark disappeared on the thirteenth floor, which further confirmed Shen Cheng's speculation that the thirteenth floor was where the boulder fell.

The last page of the report reports all the clues found on the thirteenth floor.

The first is the long friction mark, which the police have concluded through technical identification and simulation in a similar environment that the friction mark is indeed left by pushing a large stone.

When Shen Cheng and I were flipping through the appraisal report, a criminal police officer came in to report the situation.

The detective told us that they had done a number of comparative tests again. The police found a construction site with a similar environment, and also found another high-rise building, and they pushed a large stone with about the same mass, volume, and shape as the one in the murder from the thirteenth floor.

However, when the big stone falls, the place where it falls is different each time, and the tester has no way to control where the big stone will fall. Even, among the criminal police who came in and reported to us, some people thought that the murderer killed by luck.

Thirteen floors, about forty meters high, the volume of a human head is negligible, let's just think of it as a point, then, if you want to kill someone, the big stone must fall precisely on that point. The police told us with facts and actions that this is difficult.

Shen Cheng treated his subordinates very well, and he said to the criminal policeman with a smile: "You can't do it, it doesn't mean that others can't do it, let's go out first." ”

After the criminal police went out, Shen Cheng asked me if I wanted to understand, and I nodded.

When a large rock falls from a great height, it does not fall vertically, because it is pushed down. In that case, the trajectory of the large stone will inevitably appear as a parabola. Large rocks are heavy, so the force of the wind concentrated in the middle from any direction in the air is negligible.

If there is a certain force and angle, it is possible for a large stone to fall on the designated spot. It's the same as when you take a shooting theory class at a police academy, a good gunner, when shooting from a distance, has to take physics into account.

Shen Cheng smiled: "It seems that the murderer's physics and mathematics are learning well." ”

Shen Cheng's words seemed to be a joke, but they said another characteristic of the murderer, who had a middle or higher education, or had a lot of experience in physics. From the point of view of physics, it is necessary to go through very complex calculations to get a large stone from a high altitude to a designated location on the ground.

Both the angle and the thrust must be very precise, and the killer must also consider a range of other factors that can cause interference.

Soon, Shen Cheng picked up the phone on the table and notified the criminal department to measure the scene and calculate the thrust and angle required for the big stone to fall at the designated place. Shen Cheng provided direction to the criminal department, and after he asked the criminal department to get the results, he immediately went to conduct another test to see if the big stone could fall in the designated position as in theory.

Not long after hanging up the phone, another criminal police came in to report, and after a whole day of searching, they finally found the identity of the deceased. The deceased's family had a wife and children, and his family lived more than 20 minutes' walk from the construction site.

Shen Cheng and I immediately rushed to the appraisal center, only to see a woman in her forties and a teenage child crying in the lobby of the appraisal center......